Generally speaking, a snowmobile is constructed such that a slide rail is suspended from a body frame through a suspension so that an endless track runs under tension upon a drive pulley rotatably borne on the body frame and upon a driven pulley rotatably borne on the slide rail, and upon the slide rail, whereby driving power can be transmitted from the endless track to the snow surface. Here, the suspension interposed between the body frame and the slide rail is equipped to absorb vibrations which are generated by the undulations of the snow surface, and to force the endless track to follow the snow surface, thereby to ensure the snow surface drive.
However, snowmobile suspensions of the prior art use a torsion spring for a shock absorber, thereby to invite a problem that the shocks to the vehicle and its driver cannot be sufficiently absorbed in case a shock-absorbing stroke is relatively small and the undulations of the snow surface are high.
Therefore, the present invention has been conceived in view of the aforementioned problem of the prior art, and has an object to provide a snowmobile which is equipped with a suspension that it is made properly responsive to wide change in the undulations of a snow surface thereby to ensure the safety of the vehicle and the riding comfortability of the driver.